Interpretive Summary: Poultry processing facilities use large quantities of water for washing and chilling operations. The presence of dissolved minerals in process water can lead to the formation of scale that reduces the efficiency of heat transfer, for example. In poultry processing the use of hard water was shown to form scale by combining with a commonly used antimicrobial water treatment. The formation of such precipitates reduces the amount of antimicrobial available and can reduce product quality and safety. There was a strong variation in temperature with significant amounts formed at low temperatures typically used during chilling. These results are important for poultry processors interested in developing an integrated water management strategy.

Technical Abstract:
This study examined the influence of calcium and magnesium ions in process water on the solubility of trisodium phosphate. Water used in poultry processing operations may be treated with sanitizers such as trisodium phosphate to reduce microbial activity and the risk of contamination. This occurs when process water directly contacts bird carcasses, e. g., chilling or washing. The interactions between hard water ions and trisodium phosphate were evaluated with the speciation program Visual Minteq. Saturation index values were calculated for process water containing 0, 0.09, 0.18, or 0.9 mmol/kg calcium (0, 10, 20, 100 ppm) and the equivalent amount of magnesium at treatment levels of 0, 1, 5, or 10 wt% trisodium phosphate. The results showed the formation of phosphates and hydroxides in the presence of trisodium phosphate. The formation of calcium phosphate decreased with increasing temperature while magnesium hydroxide showed the opposite behavior between 0°C and 60°C. The conversion of trisodium phosphate to calcium or magnesium phosphate with subsequent precipitation would reduce the concentration of sanitizer in the process water.